Data from: Evolution of a mating preference for a dual-utility trait used in intrasexual competition in genetically monogamous populations

The selection pressures by which mating preferences for ornamental traits can evolve in genetically monogamous mating systems remain understudied. Empirical evidence from several taxa supports the prevalence of dual-utility traits, defined as traits used both as armaments in intersexual selection and ornaments in intrasexual selection, as well as the importance of intrasexual resource competition for the evolution of female ornamentation. Here, we study whether mating preferences for traits used in intrasexual resource competition can evolve under genetic monogamy. We find that a mating preference for a competitive trait can evolve and affect the evolution of the trait. The preference is more likely to persist when the fecundity benefit for mates of successful competitors is large and the aversion to unornamented potential mates is strong. The preference can persist for long periods or potentially permanently even when it incurs slight costs. Our results suggest that, when females use ornaments as signals in intrasexual resource competition, males can evolve mating preferences for those ornaments, illuminating both the evolution of female ornamentation and the evolution of male preferences for female ornaments in monogamous species.在遗传单配制交配系统（genetically monogamous mating systems）中，驱动针对装饰性性状（ornamental traits）的交配偏好得以演化的选择压力，迄今仍未得到充分研究。已有多个类群的实证证据表明，双功能性状（dual-utility traits，即同时作为异性间选择（intersexual selection）中的武器与同性内选择（intrasexual selection）中的装饰的性状）普遍存在，同时也证实了同性内资源竞争对雌性装饰性性状演化的重要性。本研究旨在探讨在遗传单配制交配系统中，用于同性内资源竞争的性状对应的交配偏好能否发生演化。我们发现，针对竞争性状的交配偏好确实能够演化，并对该性状的演化产生影响。当成功竞争者的配偶所获得的繁殖收益（fecundity benefit）较高，且对无装饰性潜在配偶的厌恶程度较强时，该偏好更易持续存在。即便该偏好会带来轻微成本，它仍可长期存续，甚至永久存在。本研究结果显示，当雌性将装饰性性状作为同性内资源竞争的信号时，雄性可演化出针对此类装饰性性状的交配偏好，这同时阐明了单配制物种中雌性装饰性性状的演化，以及雄性对雌性装饰性性状的交配偏好的演化。